Diagnosis

In some cases, PD is unrecognized, but in other cases an alternative condition leads to misdiagnosis. The diagnosis of PD is entirely clinical, there is no journey into the laboratory. During a clinical exam, the disease can be distinguished from similar conditions by the presence of upper body akinesia. In this case, there would be impaired slow movements, difficulty with initiation of action, and difficulty doing simultaneous or sequential actions. The following diseases are those most mis-diagnosed for PD. Click here for more information on related diseases.

drug induced parkinsonism

multiple system atrophy

Steele-Richardson-Olszewski disease

essential tremor

arteriosclerotic pseudoparkinsonism

Making a Diagnosis

The first step in making a diagnosis then is making sure that the patient has "true" parkinsonism. The most noticeable aspect of this is upper body akinesia. Rigidity is usually present, and there is an increase in tone of all four limbs with slightly more tonicity in the flexors. There is tremor sometimes, and the tremor characterized to be related to "true" parkinsonism is described as the classic 3-5 Hz pill rolling, pronation-supination parkinsonian rest tremor. This is not always seen, but if you have the patient count backwards with eyes closed, and hands dangling over armrests, the tremor is usually visible. A faster 6-10 Hz postural tremor may be seen instead or as well.

Importance?

Learning to correctly identify PD is very important. First, further research depends on correct diagnosis. The known cause of the disease is still unknown, and it is already difficult to formulate studies with real patients. When misdiagnosis is a factor, this becomes even more complicated. Second, it is specifically important for studying the prevalence in the population. Knowing who, how many, and what type of people have the disease aids in determining what is related to the cause of the disease. (Quinn, 1995)